1. Field of the Invention
The present invention relates to an iron alloy composition superior in corrosion and wear resistance. More particularly, the present invention relates to an iron alloy composition which confers corrosion and wear resistance upon abraded or corroded portions by coating or molding. Also, the present invention is concerned with a method for preparing corrosion and wear resistant members using the same.
2. Description of the Prior Art
In the past, in order to bestow wear resistance on iron materials various techniques including carbonizing, nitrification, induction curing, chrome plating and ceramic coating were employed. However, the iron material is treated by such techniques are not sufficiently satisfying ones because of low surface hardness, brittleness or lack of adhesion strength.
Various attempts have been made to circumvent the problems but there are still have some disadvantages. For example, low temperature sulfurizing treatment, such as caubet treatment, could bring an improvement into wear resistance but, since the treated object turned out to be poor in surface pressure resistance, the treatment is not suitable for low speed and high surface pressure conditions. Electroless nickel plating is superior to other preexisting techniques in hardness and wear resistance but it has difficulty in practical use because of the many restrictions in treatment condition and it has limit in thickening surface layer.
These various problems have forced many researchers into the developing tungsten carbide sintered alloy, which is currently the most widely used. However, it Is difficult to apply the tungsten carbide sintered alloy in various fields. In practice, it is applied only for few fields including, for example, mold materials and processing tools. The reason is that mold Is required for its manufacturing. In addition, there are many problems in Impact resistance as well as time and cost.
Recently, thermal spray techniques which use Ni-based alloy or Mo, W, Zr or Nb-based alloy have been expected to overcome the above problems. Of the techniques vitrification, by which metal is made to be vitriform, has been in the limelight because it was expected basically to surmount the aforementioned problems basically.
In 1960, Duwez introduced the possibility of manufacturing vitriform alloy by quenching molten metal into the world, which was patented in U.S. Pat. No. 3,297,436 in 1967. Since then, many related patents have been yielded. Vitrification of Fe alloy was disclosed by H. S. Chen in U.S. Pat. No. 3,856,513 and a more detailed alloy composition was suggested in U.S. Pat. No. 3,986,867 to Masumoto. However, a significant disadvantage of these alloys is that, when they are produced in bulk phase, brittleness occurs because of the redundancy of phosphorous and carbon. These materials show limited vitriform property and are short of thermal resistance. Lack of thermal resistance causes them to recrystallize from the metastable vitriform phase, resulting in a loss of vitric characteristics.